Magneto



Feb. 11, 1930.

P. BROWN El AL 1,746,378

MAGNETO Filed April 9, 1928 s Sheets-Sheet 1 j INVENTOR. 92 /dZ m BY 7%J/w QLM A TTORNEYS.

@ M "t g Feb. 11, 1930. P. BROWN ET AL 1, v

MAGNETO Filed April 9, 1928 3 Sheets-Sheet 2 a? v i/ /f/ INVENTOR.

' BYM me/@1242 #WM 7 A); 9/ a; i/ 5 ATTORNEYS.

Patented Feb. 11, 1930 UETE STATES PATENT PHELPS BBUW E AND TERRENCE G.LQUES, GE SPETHGFIELD, MASSACHUSETTS, AS-

SIGNOR-S TG VFIOO ELEGTREG COMPAB "3', OF WEST SPRINGFIELD,MASSACHUSETTS, A

GORPORATIGE OF MASSACHUSETTS MAGNETO Application filed April 9, 1928.

This invention relates to improvements in inagnetos.

The magneto is an improvement on that disclosed in the copendingapplication of Phelps Brown, filed March 24, 1926 under Serial No.97,011. The magneto of said application includes a driving mechanism bymeans of which the armature can be moved away from its poles in eitherof two ways, viz, enin ly by an inelastic transmission of force orinitially by such a transmission followed up by an elastic transmissionof force due to the expansive effort of a previously stressed drivespring. Such magneto also includes provisions for opening the primarycircuit after the armature has been seated on its poles and for holdingsaid circuit open for an interval while the armature is in contact withits poles, for the purpose of allowing the flux to build up rapidly inthe magnetic circuit.

The present invention, among other things, is directed to theelimination of the last named provisions and certain complications whichfollow from the use of such provisions. This change, however, results inthe disadvantage that the flux cannot be built up in the circuit underas favorable conditions as formerly. That is, the primary circuit, whichremains closed while the armature is in contact with its poles,exercises arestraining influence on change of fins in the magneticcircuit, wherefore the in builds up more slowly in the magnetic circuit.Under such conditions, the armature actuating mechanism of the priorapplication is not satisfactory in so far as the advance or high speeddrive is concerned. Therefore, one of the problems with which thisinvention is concerned is the development of an armature actuatingmechanism which will afford a satisfactory advance or high speed driveunder the aforesaid condition.

According to this invention, the armature actuating mechanism for theadvance or high 1 speed drive has been changed from that of theaforesaid application in such ways as to introduce factors which offsetthe disadvantage due to building up flux against aclosed circuit primarywinding. These factors are increased time for the building up of theflux Serial No. 268,706.

and increased speed in the early stage of the armature movement. Thefirst factor results from arrangements which permit the armature toremain in contact with its poles for a substantial interval. The secondfactor results from the injection into the former advance drive, whichwas solely by inelastic transmission, of a spring impulse occurring inthe early stages of the armature flight and directly following theunseating of the armaturc from its poles.

While th advance or high speed drive is broadly similar to the retard orstarting drive, the fact isthat they are not equivalent. The high speeddrive would not be effective at cranking speeds and the starting drivewould not be suitable for high speed work, notwithstanding that eachutilizes a spring impulse. This is explained from the fact that theimpulse of the spring is added to 7 the kinetic energy imparted from thedrive shaft. In high speed work, the spring is moving rapidly at thetime when it expands and produces the impulse, while at cranking speedstne drive shaft turns so slow that no material kinetic energy isimparted to the spring, and the spring impulse has to be re lied on todo all the work. Thus, the spring impulse used for starting would, ifused for high speed, be too violent and produce over- 30 throw of thearmature while the spring impulse used on the high speed drive would, ifused for starting, be insufiicient to move the armature fast enough.Accordingly, it is necessary to have different degrees of springimpulse.

To secure the requisite degrees of spring impulse for the two differentoperating conditions necessitates another change which consists in theuse a drive spring initially 9o stressed to a substantial degree, asdistinguished from the substantially unstressed drive spring of theprior application. The two parts, between which the spring is interposed, have to engage and elfect the inelastic transmission for thearmature tripping function at an earlier time for the high speed drivethan for the starting drive, which means that much less relativemovement of these parts is available on the high speed drive, So little1% of such relative movement is available that an initially unstresseddrive spring would not be stressed enough for the work in hand and thearmature, in the initial part of its flight,

would lag to such an extent that it would not efiect separation of thebreaker points at any earlier time than with the starting drive,notwithstanding that the armature started earlier. It is necessary notonly to start the armature in its flight at an earlier time but also tomake it reach-the breaker point opening position at an earlier time.

The invention has other features relating to improvements in variousparts of the magneto other than the armature actuating mechanism. Thesefeatures can best be set forth in the following description and theywill be particularly point-ed out in the appended claims.

The invention will be disclosed with reference to the accompanyingdrawings, in which Figs. 1, 2 and 3 are small scale exterior elevationalviews showing the rear and the left and right ends, respectively, of themagneto;

Fig. 4 is a sectional elevational view taken on the line 4-4 of Fig. 3;

Fig. 5 is a bottom plan view, showing the magneto as it appears when thelower housing is removed and showing the armature driving mechanism inone of its two operating positions;

Fig. 6 is a fragmentary bottom plan view, taken similarly to Fig. 5 butshowing the armature driving mechanism shifted into its other operatingposition;

Fig. 7 is a cross sectional view, taken on the line 'Z7 of Fig. 4 andillustrating the armature driving mechanism;

Fig. 8 is a sectional elevational View taken on the line 8-8 of Fig. 0,

Fig. 9 is a top plan View showing the magneto as it appears after thecap has been removed;

Fig. 10 is a sectional view taken on the line 10-10 of Fig. 8;

Fig. 11 is a cross sectional view taken on the line 11-11 of Fig. 1; and

F lg. 12 is a fragmentary cross sectional view taken on the line 1212 ofFig. 5.

The magneto includes a source of magnetic flux (Fig. 4) which comprisesa series of short bar magnets 15; a magnetic circuit from said source,comprising two cores 16 connected one to each polar extremity of saidsource, and an armature 17 which is pivotally supported for movement toand from the lower ends of the cores; mechanism for reciprocating thearmature from a rotary drive shaft 18; electrical windings comprisingtwo primary coils 19 and two secondary coils 20; an interruptermechanism comprising cooperating and relatively movable breaker points21 and 22 (Fig. 11) adapted to be separated by armature 17 at apredetermined point in'its flight away from cores 16 to open thenormally closed primary circuit in which coils 19 are included, therebyinducing an electromotive force in the secondary coils; and a condenser23 associated in the usual way with the interrupter. The armaturedriving mechanism includes a starting or low speed drive and a normal orhigh speed drive and is also so arranged that a retarded spark issecured with the first form of drive and an advanced spark with theother form of drive. particular form of armature drive desired is madeby shifting a lever 24 and the movement of this lever also controls thetiming of the spark.

All parts of the magneto, except for lever 24, part of drive shaft 18and certain electrical terminals, later to be described, are encased bythree members A, B and C, as will be plain from Figs. 1, 2 and 3. Themember A, as shown, is a one piece molded member of bakelite, or othersuitable material. In this member substantially every part of themagneto is assembled, after which the parts B and C are applied to thelower and upper ends, respectively, of member A to house in the parts,which project beyond such ends. The member C is a pressed metal capadapted to tightly'fit about the top of member A, as indicated in Fig.4. The member B is a hollow metal base, much like a crank case, which inaddition to housing the The selection ofthe armature and its drivingmechanism, also serves to contain the supply of lubricant and the meansfor distributing the same to the various moving parts. The member Arests upon the top of the upstanding marginal walls of member B and agasket :25 (Fig. 7) partially imbedded in a groove in said top, sealsthe joint between the abutting parts. The parts A and B are heldtogether by a pair of studs 26 (Figs. 4 and 5) and a cap screw 27 (Figs.4 and 11). The latter passes upwardly through base B and threads into ametallic insert 28 in member A. One end of each stud 26 is imbedded inthe member A during the process of molding of the same. These studsdepend from member A on opposite sides of the drive shaft 18 and passthrough openings in one end wall of base B. Nuts 29, threaded on thelower ends of studs 26, serve to draw the parts A and B together.

Referring now to the electrical windings, these are housed within thebakelite member A, which is provided with a pair of openings extendingvertically therethrough for that purpose. These openings, as shown inFig. 4, ar larger at the top than at the bottom leaving annularhorizontal shoulders 30, on which the secondary coils 20 rest. There arealso shoulders 81 which serve to support the primary coils. Onesecondary coil (that on theleft in Fig. 4) has, as one terminal, acopper strap 32 which passes upwardly out of the coil receiving recess.One terminal of the iyasysve other coil is connected to the high tensionterminal button 33 of the ma neto. The inner end of this button isreceived n a recess in the outer wal of member A and s secured theretoby a hollow rivet 3 1, prior to the insertion of the secondary coil. Theterminal wire 35 of this coil is 13?. led through the hollow rivet, asthe coil is set in place in its recess, and the wire is afterwardssoldered to the button near its outer end. The two secondary coils areconnected together by a wire 36 which is covered by an insulating strip37. The memher A is provided with groove 38 (see also Fig. 11),extending between the coil receiving penings, to rec ive the wire 36 andstrip 37. Each primary coil 19 is wound on a tubular core 39 and thenset into a cup 10. The latter has an opening in its base of the properdiameter to receive the lower end of core 39 which terminates flush withthe base of the cup. This cup is slipped through the secondary coil 20and its base rests on shoulder 31. The upper end of each cup is filledwith suitable sealing compound, indicated at 11. Each cup has anoutwardly turned flange 412 which overlies the top of the adjacentsecondary coil and closes off the opening in member A, exceptfor a smallannular space through which strip 32 passes. This space is then filledwith sealing compound as indicatd at 13. Sealing compound may also beapplied at the base of each cup 40, as indicated at 44. The lead wiresfor the primary winding are shown at 15 and 46 and the two coils of thiswinding are connected together by a wire 47.

The member A. at a point midway between its coil receiving recesses butnear its back wall, is provided with a cylindrical recess open at thetop, into which the condenser 28 (of roll form) is placed, as shown inFig. 11. The terminals of the condenser (a short bare copper strip 18and an insulated wire %9) are led upwardly out of the recess and theupper end thereof is suitably sealed, as indicated at 50.

Disposed near the front wall of member A and opposite the condenserreceiving recess is a cylindrical recess 51 which extends upwardly fromthe base of member A but terminates short of the upper wall thereof.Inset into the closed upper wall of recess 51 is a metallic piece 52.which is threaded to receive a stud 53. The latter, at its lower end,carries the fixed breaker point 21 and its upper end is provided, asshown, with a screw slot, whereby the breaker point 21 may ie verticallyadjusted when cap C is removed. A lock nut 54 serves to preserve theadjustment of the fixed breaker point and also to hold in place theterminal piece 55. The latter has a down-turned lug 56, which entershole 5? in member 52 and thereby holds piece 55 from turning. The hole5'? serves to vent the recess 51 to the interior of cap C,

which as will appear is vented to the atmosphere. The other terminal 22of the interrupter is carried by a plunger 58 having two axially spacedbodies 59 of felt or the like. which slidably engage the bakelite wallof c}. inner 51 and require no lubrication. The lower end of plunger 58has a flange 60, which is engaged by a spring 61. The latter, one end ofwhich is frictionally held in a hole in. base A, tends to hold thebreaker points 21 and 22 in engagement. An opening, leading from thefront wall of member A and intersecting recess 51, is provided to permitinspection of the breaker points. This opening is normally closed by acuplike part 62 which snugly fits, and is frictionally held in place, inthe opening.

he stationary members of the magnetic circuit are first assembled andthen applied as a unit to the member A. Each core 16 is made up oflaminations and these laminations are bound together in any suitableway, as by a rivet 63 (Fig. near its lower end and a bolt 6-1 near itsupper end. The lower extremity of each core, which constitutes a polarface adapted to be engaged by armature 17, is of somewhat less crosssectional area than the body of the core, thereby intensifying the fluxat such polar face. The cores 16 are provided near their upper ends withconfronting recesses in which the polar extremities of the bar magnets15 are received. These magnets are suitably held in said recesses, as bywedges 65, which are driven in between two adjacent magnets of thestack. The two cores 16 are tied together by a pair of cross bars 66(Fig. 9) which are held in place by the bolts 61', above described. Eachof these cross bars has an outwardly turned horizontal flange 67 whichis adaptec to rest upon the upoer face of member A (Fig. 11) and to besecured thereto by cap screws 68. The flanges 67 are centrally recessedto allow access to the condenser and the upper terminal of theinterrupter.

After the cores, magnets and cross bars have been assembled, this unitis slipped in place by passing the cores downwardly into and through thespools 39 of the primary coils. This unit is properly located relatively to block A by the abutment of the lower magnet 15 with seats @9 11),provided in the upper face of member A, and by the abutment of theflanges 67 with said face. lrior to slipping cores 16 into spools 39,the secondary ground terminal a strip of bare copper. is bent downwardly(Fig. so as to lie in the bore of the lett hano. spool and so as to lieat an acute angle to the axis of said bore and in the path of the lefthand core 16. Then, when the latter is pushed into place, it engages andflex s the sp g end of terminal 32, whereby said terminal is grounded tosaid core. The ground terminal 418 of the condenser is bent so as tounderlie one of the flanges 67 (Fig. 9) and become electricallyconnected thereto when the cap screws 68 are applied. Having appliedthese four caps screws, the magnetic field unit is securely fiXed tomember A.

The electrical connections of the primary circuit are then completed.The terminal wire and the lead wire 49 of the condenser are connected tothe terminal of the interrupter (Fig. 9). The primary terminal wire 16,as well as a ground wire 70, are connected to a terminal 71 which issecured by one of the cap screws 68 to one or the flanges 67. The groundwire 70 (Figs. 5 and 9) passes downwardly through the spool 39 of theright hand primary coil. The cores 16 are of square cross section,except that their edges are chamfered. Consequently, when the cores areplaced in spools 39, four passages 72 are left between each core and itsspool. These passages extend from the base to the top of member A andafford ventilating ducts for the hollow base B. One of these passagesalso serves as a conduit for the ground wire 7 0.

On the base of member A (Figs. 5 and 12) is a stud 73 having a nut 7% bymeans of which a spring contact 7 5 and a terminal piece 76 are clampedin place. The wire 70 is secured to terminal 7 6. When the housing B isput in place, one of its side walls engages and flexes the springcontact 7 5, whereby a good ground connection is had to base B (the partwhich is adapted to be bolted to the engine). It is to be noted that theground wire 7 0 affords a good electrical connection directly to thegrounded terminals of the primary, secondary and condenser, and that theground circuit path does not include any moving parts of the magneto.The ground connection for the interrupter is made dir etly to base B bymeans of spring 61 (Fig. 11) which constantly engages the plunger 58 towhich breaker point 22 is secured. This plunger is periodically moveddownwardly by a lug 77 fixed to armature 17 and this lug is insulatedfrom the armature by suitable means including the strip 7 8 so as toexclude the armature from forming any part of the path of the groundcircuit. Heretofore, when the armature has formed part of such path, ithas been found that the oil in the armature hinge bearings has beencarbonized. By insulating the lug 77 from the armature, this difficultyhas been overcome.

To avoid the general difficulty of the harmful effect on the lubricatingoil by ozone liberated within the closed magneto casing, the same isfully ventilated. The fines 72 adequately vent the lower housing to thespace within cap C and the interrupter cylinder 51 is likewise vented toSaid space, as heretofore described. To complete the venting system, ahole 79 is provided centrally in cap C (Figs. 4 and 11). Overlying thisopening is a curved plate 80, which may be the name plate of magneto,and this plate is suitably secured as by rivets, to the indented centralpart of cap G, in such a way that a slight space is left between theplate and cap at the point where the plate overlies hole 79. Secured tothe inner wall of cap C and underlying hole 7 9 is a piece 81'of springmetal which is sufiiciently spaced from cap C to allow communicationbetween hole 7 9 and the interior of cap C. The plate 80 and piece 81make it difficult for water or dust or dirt to enter the magneto, Thepiece 81 has two depending prongs 82 (Fig. lVhen cap C is pressed inplace, the lower and inturned ends of prongs 82 engage the bevelled topedges of cores 16, whereby the prongs are thus flexed outwardly andguided so that they will slide down along the vertical outer faces ofthe cores. The prongs thus press against such faces and frictionallyhold the cap C in place.

The member A has formed thereon a pair of axially alined bearings 83 and8% (Figs. 5 and 8) which depend from the lower face of the member nearthe rear wall thereof. These bearings are provided with metallicbushings 8:3 and 86 (Fig. 8) suitably fixed in place during the processof molding member A. B0- tatably mounted in these hearings is a hollowshaft 87 to which armature 17 is suitably fired. As shown in Figs. 5 and11, the armature is secured by cap screws 88 to a pair of blocks 89 andthese screws also serve to hold the lug 77 to the armature as well as toclamp the laminations of the armature together. Each block 89 is boredto receive shaft 87 and is slotted, as at 90, and provided with a capscrew 91, which acts to draw together those parts of the block which lieon opposite sides of slot 90 and thus bind the block securely to shaft87. ()ne of these blocks substantially abuts an end of bearing bushing85 and the other substantially abuts the adjacent end of bearing bushing86, whereby shaft 87 is held within small limits against axialdisplacement. The armature is normally held in contact with the lowerfaces of cores 16 by magnetic attraction. The breaker point returnspring61 serves to move armature 17 upwardly and sufliciently into the fieldof magnetic attraction so that the remainder of its upper flight may becompleted by magnetic attraction The member A (Figs. 41 and 12) isprovided with a bearing 92 depending from its base and provided with ametallic bushing 93. This bearing receives the small inner end 18 ofdrive shaft 18. Between the end 18 and the main body of drive shaft 18(Fig. 4) an eccentric 94 is formed thereon, and over this eccentric isplaced a loose ring 95 (see also 7), which functions as an anti-frictionroll. Beyond the eccentric is a main bearing bushing 96 (see also Fig.5), which is clamped between members A and B of the studs 26 and nuts29, above described. This bushing is provided with a longitudinal grooveto receive a key 97 formed on member A, whereby it is properly locatedangularly and held from turning. Bushing 96 is likewise milleo out, asshown in Fig. 5, to form a shoulder 98 which is engaged by a washer 99tting tightly on one of studs 26. When this washer is pressed downagainst the shoulder 98, the bushing will be properly locatedlongitudinally of member A and held against axial displacement. Washer99 also serves as a convenient means for holding the bushing in placeduring assembling operations.

The eccentric 94 operates through a pair of levers 101 (Figs. and 7) and102 to move the armature away from the polar faces of cores 16. Theselevers are pivotally mounted on armature hinge shaft 87 and are free toturn thereon and free to turn relatively to one another within the smalllimits necessary. These levers, instead of operating directly onarmature 17 are arranged for convenience to operate on an arm 103, whichis fixed to shaft 87 and arranged adjacent to the levers 101 and 102.Thes levers and arm 103 lie in the space between bearings 92 and 96(Fig. 4), extend transversely of shaft 18 and underlie eccentric 94:.The arm 103 (Figs. 5 and 12) is riveted at 1 to one arm of a split hub105 which is clamped to sh ft 87 by means of a cap screw 106. The lever101 has suitably fixed thereto a hub 107 (Figs. 7 and 8) which isslidable as well as turnable on shaft 87 Lever 102 has fixed to it asimilar hub 108 which fits over hub 107. A pin 109 passes diametricallythrough both hubs 107 and 108 and through a diametrical slot 110 in oneend of shaft 87 Hub 107 is slotted at 111 to receive pin 109 and permitthe necessary relative turning movement between the hubs. The slot 110is wide enough to afford enough freedom to pin 109 to permit both hubsto turn on the shaft throughout the desired range. Slot 110 also permitsthe levers 101 and 102 to be axially shifted from the position shown inFig. 5 to that shown in Fig. 6. A spring 112, encompassing hub 108. actsbetween an end wall of base B and lever 102 tending to hold the l vers101 and 102 in the position shown in Fig. 5. The levers 101 and 102,when shifted to the position shown in 6, are limited in their movementby the abutment of pin 109 8) with a pin 113 which is fixed in shaft 87and passes diametrically through the latter at right angles to slot 110.

The levers 101 and 102 at their outer extremities have projections 11 1and 115 (Fig. 7) which extend inwardly toward one another and areadapted under certain conditions to abut, whereby an inelastictransmission of force from lever 101 to lever 102 may be effected.Between said extremities is a drive spring 116 in opposite ends of whichthe projections 11 1 and 115 are received. This drive spring, when putin place, is under an initial tension of substantial degree. To preventthe tensioned spring from spreading the levers 101 and 102 apart (beyondthe limit shown in Fig. 7), a lug 117 is struck out from lever 101 andthis lug underlies lever 102 and engages the same for the statedpurpose. The arm 103, which moves, and moves with the armature has twolugs 118 and 119 struck out from its lower edge. These lugs, as shown inFig. 5, are of different width and disposed at different radialdistances from shaft 87. The lug 118 is closer to the shaft and of lesswidth than lug 119. Vlhen the levers 101 and 102 are positioned as inFig. 5 (which may be termed the advance or high speed drive position)the lug 118 underlies lever 101; but when these levers are shifted tothe retard or starting drive position shown in Fig. 6, lug 118 will nolonger lie in the path of the l ver 101. The lug 119 is wide enough sothat it lies in the path of lever 102 in both positions of this lever.The weight of the levers 101 and 102 normally holds the latter inengagement with lug 119, as shown in Fig. 7.

Assumi g that the levers 101 and 102 are in the starting position shownin Fig. 6, the depression of lever 101 by eccentric 94 will cause nomovement of lever 102 and arm 103 until the projections 11 1- and 115abut. This follows because lug 118 does not lie in the path of lever101. It is to be noted that drive spring 116, even when fully stressed,is not powerful enough to overcome the force '1 magnetic attraction,which holds the armaure to cores 16 and therefore holds arm 103 theposition illustrated in Fig. 6. Conseouently, as lever 101 is depressedby eccentric the arm 103 and lever 102 remain stai-o ary while thetension of spring 116 is inreased as lever 101 moves toward lever 102.Continued movement of lever 101 will cause the engagement of projections114 and 115 and there then results an inelastic transm ssion of forcefrom the drive shaft through levers 101 and 102 to lug 119 of arm 103,whereby the armature 17 is nr ed off its poles and started in itsdownward flight. Once the armature has been separated from cores 16,even by a very slight air gap, the force exerted on the armature bymagnetic attraction, is so much lessened as to be inferior to that ofthe stressed drive spring 16, wherefore the latter expands and rapidlymoves the armature.

Assuming that the levers 101 and 102 are positioned as in Fig. 5, thenas lever 101 is moved downwardly by eccentric 94, this lever will engagelug 118 before the projections 11 1 and 115 can engage. This results inincreasing the stress of the drive spring 116, but not to so great anextent as before because the levers 101 and 102 move toward one anotheronly a short distance before lever 101 abuts lug 118. It also results intrippiiig the armature,.i. e., breaking the magnetic hold thereon andinitiating the downward flight thereof,-at an earlier point in therevolution of drive shaft 18. (lnce the armature has been tripped, thedrive spri 116 comes into play for a short interval (until the springmoves lever 102 into abutment with lug 117) and moves the armature bymeans of the lever 102 and abutment 119 of arm 103. Although the drivespring can act only for a short interval, it nevertheless produces, dueto its initial stress, a sufficient impulse to accelerate the movementof the armature in the earlier stages of its flight. After spring 116has thus acted and has spread the levers apart to the limit permitted bylug 117, the remainder of the flight is completed by the action of theeccentric which follows up the momentary spring impulse with a positivedrive which is virtually inelastic since spring 116 does not yield.

The driving levers 101 and 102 are shifted from one to the other of thedescribed positions by means controlled by the above, described lever24. The latter is fixed to a cam 120 (Fig. 8), which lies within oneendof the hollow shaft 8?. Cam 120, when turned, serves to move axiallyinward a cam follower 121 which slides in a diametrically disposed slot122 in said end of shaft 87. The follower 121 acts (preferably through aspring 123) to move a rod 124, which is slidable in shaft 87, and thelatter abuts the described pin 109 and thus moves the interconnectedlevers 101 and 102. The shifting of these levers should be efiectedwhile the armature is on its poles so that neither lever will be bearingagainst the lugs on arm 103 under any great pressure. The spring 123enables the shiftto be effected at the proper time irrespective of thetime when lever 24 is moved. If, when lever 24 is turned, either lever101 or 102 is being forced against the lugs 118 or 119, respectively,the spring 123 simply compresses without moving rod 124. Subsequently,when the pressure between the described parts is relaxed, spring 123will expand and move rod 124 to shift the levers. The shifting of ti elevers 101 and 102 back from the position shown in Fig. 6 to that shownin Fig. 5 is effected by spring 112 after lever 24 has been moved topermit. Spring 112, like spring 123, will not necessarily effect theshift immediately when lever 24 is turned but the action will bedeferred, if necessary, until the pressure between levers 101 and 102and 103 is relaxed.

Cam 120 has a cylindrical part 125 of less diameter which is rotatablein one end of arm 126. The other end of this arm is fixed bycap screws127 to an end wall of base B (Fig. Beyond part 125 is hexagonal part 128and beyond the latter a threaded end 129. A'cupped spring washer 130'is'first placed on part '128 and this is followed successively by awasher 131' and lever 24, after which a nut 132 is applied to thethreaded enc 128, thus holding the lever 24, washer 131 and cam 120 inplace relatively to arm 126. "Washer 131 has an car 133 which is struckoutwardly therefrom and which rides in an arcuate recess 134 (Fig. 10)formed in arm 126, and the end walls of this recess limitthe movement oflever 24 and define the proper positions of the latter for retard andadvance drive. The cam 120, lever 24 and washers 130 and 131 areassembled on arm 126 before the latter is fastened to base B. Then afterbase B has been put in place, rod 124, spring 123 and cam follower 121are successively dropped into the hollow shaft 87. Then the cam 120 isslipped into the open end of shaft 87 and arm 126 is fastened to base B.The cam 120 closes the end of shaft 8? and the arm 126 seals thisclosure, making it difiicult for dust and dirt to enter the hollowshaft.

For lubricating the moving parts of the magneto, an absorbent pad 136(Figs. 4,8 and 11) is placed in the bottom of the housing B and soakedwith oil. Oil may be supplied to this pad through an opening in thehousing B, such as that opening which is normally closed by the screwplug 13. (Fig. 1).' Oil from this pad is led to the various bearings bywicks, which are preferably reinforced by a metal wire and may besimilar in con struction to the familiar pipe cleaner. A wick 138 (Fig.8) leads from pad 136 up wardly through the lower part of bearing 83 andinto an annular groove in bushing 85. A wick 139 leads from pad 136 andenters a longitudinal groove in shaft 87, lying between the shaft andbushing 86. A wick 140 leads upwardly from pad 136 into a longitudinalgroove in bushing 93 (Fig. 4) and then passes downwardly back to thepad, in such a way that one end face of eccentric 94 and roll 95 bearagainst the wick. A wick 141 leads upwardly from pad 136 and into alongitudinal groove in the main bearing bushing 96. The latter has acircumferential groove 142 in its outer periphery to collect oil whichmay creep outwardly and such oil drains to the bottom of the groove andthence to the housing B as shown in Fig. 4.

After the armature and its driving mecha-' nism have been assembled, allof which is accomplished before housing B is applied and while themagneto is inverted, the pad 136 is laid in position resting on top ofthe armature. The various wicks, which have previously been placed intheir respective bearings, are passed through holes in the pad and thenbent over on top of the pad. Then the housing B is applied, bolted inplace and the mag neto righted up so that the pad 136 drops to thefioorof the housing with the bent over ends of the wicks therebeneath.

It is to be noted that the armature bearings tired in integralextensions 88 85 and 86 are and 8 or" the balrelite member A. however,housing B is applied, it supports both of these hearings as well as themain bearing 96. Elie part 8 1 is grooved out as shown in 5 to 'eceivethe housing and the bearing i itorms the bottom of this groove is recnasemi-circular seat in housing B n i The latter has an integralupstanding part (Figs. 1 and 8), the upper edge of w rich forms asupporting seat for member 83. e main bearing ushing 96 is, of course,supported directly by the housing B.

it desired, a termina be provided on cap C from. Connected with this thecap is a spring w which, when cap C is against iii brig insulatedterrupter. T rmin hinting nut 145 so tot. thereto.

suitable way to nection when desiret for th h circuiting the primarycoils s magneto.

In operation, the drive sha; connected to moving part as to becontinuousl i rotated t er relative speed. Qnce each evolution. ecentric 9% will engage and depress lever 10 thereby increasing thesire?" oi the spring d subsequently pr titre 1'? off its cores. Followinor tripping ot the armature, d. spring moves the armature away from itspoles and at a predetermined point in the downwarc he the armsture lug 7'es the flange of breaker point plunger 08b separation of This opens theand an eleche secondary erebv at and hitherto closed rimary circuitt-romotive force is Coils. The spring 01 returns the armature to wardsits poles enough so that the remainder ot the flight can be compl ted bymagnetic attraction. l hat the need in it will he notes.

breaker Joints close when spring ceases to move the armature upwardly. il final partof the upward flight of the arr-nature is made against ashortcir uited primary which tends to lessen the violence or th finalmovement of the armature. This arrangement, coupled with the shockabsorbing ettect of spring 116, enables the armature to he seated on thecores 16 with comparative quietmess.

The drive spring, because it is under substantial degree of initialstres otters efiective resistance against the sucking in of the armatureby magnetic a traction in. the latter stages of its flight toward thecores, whereas aspring which is initiaily unstressed would not do so.When spring drive is used, the eccentric 94 does not have full co -trolof the return flight or" the armature as it would if the transmissionwere inelastic. lVhile the eccentric controls the movement of lever 101,t e lever 102 may move upwardly ata faster rate because the armature isdrawn towards its poles by magnetic at traction and the interposedspring 116 may yield to permit this action. It is important therefore,to use the initially stressed drive spring because it prevents anuncontrolled suck in of the armature such as would tend to result in anoisy sea-ting of the armature on its poles. At the same time, thespring can and does yield somewhat which is an advantage because thearmature becomes seated on its poles at a slightly earlier time thanwould be otherwise possible. Thus, the period of dwell of the armatureon its poles is lengthened. As will be plain from Fig. 7, there isconsiderable lost motion between the lever 101 and eccentric 94, whenthe latter is in its uppermost position. The eccentric can be turnedthrough a considerable angle (approaching 180 degrees) without removingthe armatur from its poles. The dwell interval thus afiorde'd, augmentedby that due to the compression of spring both at the start of thedownward flight and at the end of the return flight of the armature,allows time for the flux to build up sufiiciently even under theunfavorable condition of a closed circuit primary winning.

In view or" the unfavorable condition under which the fiux is built upin the magnetic circuit, it is desirable to compensate for thedisadvantage by resorting to a spring impulse on direct drive. YVhilethe long dwell or" the armature on its poles also compensates in partfor the aforesaid disadvantage, it is usually necessary, or at leastdesirable, to insure a speedy start of the armature in the early stagesof its flight, and this is effected by the spring impulse, characterizedin that t 1e drive spring is initially stressed to a substantial degree.T he necessity for the initial stress in spring 116 will best appearfrom a consideration of what happens it one starts with an unstresseddrive spring, such as was formerly used for th spring impulse start ingdrive, and tries to get a spring impulse in the high speed drive and atthe same time secure an advance in the timing of the spark. The obviousplan would be to bring the abutments 114 and 115 closer together in aneffort to get spark advance on the high speed drive. This would allowsome compression of the drive spring and would start the armature fromits poles at an earlier time. Experimerits in this direction show thatno advance in spark is obtained, notwithstanding that the armaturestarts earlier, because the greatly lessened stressing oi? the drivespring rcsults in a force, which is inadequate to move the armature fastenough to arrive at breakerpoint opening position earlier than it did onthe starting drive. In other words, to secure spark advance, it is notenough to sim ply start the armature in motion at an earlier time butmeans must be provided to insure that the armature arrives at saidposition at an earlier time. If, however, the spring is always undera'substantial initial stress, a substantial force is available to imparta kick to the armature and move it rapidly towards said position so thatthe desired spark advance is obtained even through the movement oflevers 101 and 102 towards one another is limited. Just as soon as thelevers 101 and 102 move toward one another even by a small degree, theforce of the stressed spring is available to move the armature and,immediately following the prying of armature off its poles, the springexerts this force and imparts the impulse. This impulse is necessarilyof short duration, but it is nevertheless suihcient under high speeddrive conditions because the force of the spring is added to that due tothe l'inetic energy of the rapidly moving levers. Also it should benoted that due to the lost motion between the eccentric 9a and lever101, the latter will be rapidly moved by the eccentric and suddenly putinto motion, as distinguished from the slow initial motion which wouldoccur if the lost motion were not present.

Thus, a speedy movement of the armature is effected which, taken withthe long dwell of the armature on its poles, is the key to the solutionof the problem of making the mag neto operate satisfactorily on highspeed drive under the unfavorable condition due to building up fluxagainst a closed circuit primary winding. By the use of an initiallystressed drive spring interposed between two members, such as 101 and103, the desired spark advance may be obtained by causing the inelastictransmission between these members to occur earlier and at the same timean effective spring impulse is obtained for the high speed drive. It isto be noted that the inelastic transmission is effected on direct driveby the direct engagement of members 101 and 103 and on starting drivethrough the intermediary of lever 102. This lever may be considered as apart of member 103 (since it always moves therewith) which is interposedsimply to enable spring 116 to be shifted easily in a lateral direction.The parts which are important for the driving functions are 101 and 103.

The magneto is also characterized by other features of improvement suchas the means for shifting the armature actuating mechanism from one tothe other of its two positions. The utilization of the hollow hingeshaft of the armature for the reception of connections to transmit amovement from lever 24, which lies wholly without the casing, to thearmature actuating mechanism, which is completely enclosed within thecasing, is thought novel and important. The insulation of the lug 77important, as well as other provisions, which afford definite electricalpaths to the ground (housing B) and avoid the possibilities of straycurrents passing through bearings and effecting carbonization of the oiltherein.

A most important feature of construction relates to the manner in whichthe stationary elements of the magnetic circuit are arranged andmounted. These elements are secured to the top of member A and are soarranged that the length of the cores 16 is reduced to a minimum. Theframe, which was formerly interposed between the base of coils 19 andthe armature and to which the cores were secured, has been eliminated,thus permitting shortening of the core. So also, the cross bars whichinterconnect the cores and were formerly applied above the coils andbelow the magnets, have been raised so that the lowest magnet of thestack now virtually rests on top of the secondary coils. Fig. 4 willmake this plain and will show that the dis tance from the lower face ofthe lowest magnet to the lower polar face of the cores is only slight ygreater than the height of the coils. A considerable saving in thelength of the cores has therefore been effected by the illustratedscheme of supporting theisaine from the top of member A. That is, thecross bars 66 have the outwardly turned parts 67 which rest upon andaresecured to the top of member A. This gives a suihciently rigidsupport for the stationary elements of the magnetic field withoutnecessitating any extra length of the cores for the purpose. The flanges67 rest on seats on member A, which insures proper location of the polarfaces of the cores with respect to the armature. In addition, the lowermagnet 15 may also seat on member A, as'shown in Fig. 11 to secure addedrigidity of support. The cores 16 also tightly fit within the tubularcores 39 of the primary coils and this contributes to the stabil-v ityof the support ofthe magnetic field elements.

The invention has been disclosed herein, in an embodiment at presentpreferred, for

illustrative purposes, but the scope of the invention is defined by theappended claims rather than by the foregoing description.

What we claim is:

1. Armature driving mechanism for a magneto, comprising, two membersrelatively movable in a direction toward and away from one another andrelatively shiftable in another direction from one position to another,one of said members being connected to the armature, means for applyinga driving force to the other member to move it in the first nameddirection, said means operable on the last named member in either of thepositions towhich said members may be from the armature is alsorelatively shifted, resilient means associated with said members andarranged to be increased in stress to a substantial degree when saidmembers while in either of said positions are relatively moved by saiddriving force, and to be increased in stress to a greater degree whensaid members occupy one of said positions than when shifted into theother position.

Armature driving mechanism for a magneto, comprising, two membersrelatively movable in a direction toward and away from one another andrelatively shiftable in another direction from one position to another,one of said members being connected to the armature, means for applyinga driving force to the other member to move it in the first nameddirection, said means operable on the last named member in either of thepositions to which said members may be relatively shifted, resilientmeans associated with said members and arranged to be increased instress to a substantial degree when said members while in either of saidpositions are relatively moved by said driving force, and means forlimiting the degree of relative movement of said members by said drivingforce and to different degrees according to the position to which saidmembers are relatively shifted, said limiting means effecting aninelastic transmission of force to initially move the armature, suchtransmission being followed by an elastic transmission from the stressedresilient means to the armature.

3. Armature driving mechanism for a magneto, comprising, an assemblyconsisting of two levers pivotally connected and held aga'mst spreadingapart beyond a predetermined extent and a drive spring interposedbetween said levers under asubstantially initial stress and tending tohold the levers spread to said extent, a member connected to thearmature and engaged by one of said levers, such lever being laterallyslidable on said member, means for applying a driving force to the otherlever to move it toward the first named lever and increase the tensionof said spring, said levers adapted to engage after the tension of saidspring has been increased to a predetermined degree and effect aninelastic transmission of force to said member to initiate the movementof the armature, said assembly being bodily shiftable laterally to aposition wherein the second lever when moved toward the first lever willfirst increase the stress of said drive spring but to less than the lastnamed degree and will then directly engage said member and effect aninelastic transmission of force to the armature.

4. In a magneto, an armature, a member connected thereto for moving thesame, a drive shaft, and relatively movable members interposed betweensaid drive shaft and first named member by which an inelastictransmission from said shaft to said member may be effected, resilientmeans arranged to be increased in stress as said second named membersare moved to effect said inelastic transmission, said second namedmembers being bodily shiftable from one position to another andinitiating said inelastic transmission at an earlier point in therevolution of said shaft when in one position than in the other, andeffecting less increase in the stress of said means when saidtransmission is initiated earlier than when initiated later.

5. In a magneto, of the type wherein an armature is moved into and outof contact with magnetic pole pieces, primary and secondary windingsassociated with said pole pieces, a normally closed electrical circuitincludin said primary winding, means operated from the armature at anintermediate point in its flight away from said pole pieces to open saidcircuit, a drive shaft, an armature actuating mechanism operativelyinterposed between said shaft and armature and bodily shiftable from oneposition to another to effect said flight of the armature in either oftwo ways, said mechanism in each position effecting an inelastictransmission of force from said shaft to the armature to initiate saidflight of t e armature and including means to impart a spring impulse tothe armature following its initial movement, said mechanism when in oneof said positions initiating the movement of the armature at an earlierpoint in the revolution of said shaft than when in the other positionand effecting less of a spring impulse insufficient of itself to movethe armature to said intermediate point.

6. In a magneto of the type in which an armature is moved into and outof contact with magnetic pole pieces, a hollow shaft to which thearmature is fixed, a member fixed to said shaft, a drive shaft,mechanism interposed between said drive shaft and member and bodilyshiftable from one position to the other for effecting operation of thearmature in either of two ways, means enclosing the aforesaid elementsexcept for one end of said hollow shaft, a lever mounted on said meansto control the movement of said mechanism from one position to theother, and connections from said lever to said mechanism including apart disposed in said hollow shaft.

7. In a magneto of the type in which an armature is moved into and outof contact with magnetic pole pieces, a hollow shaft to which thearmature is fixed, a member fixed to said shaft, a drive shaft,mechanism interposed between said drive shaft and member and bodilyshiftable from one position to the other for effecting operation of thearmature in either of two ways, means enclosing the aforesaid elementsexcept for one end of said hollow shaft, a lever mounted on said meansto control the movement of said mechlit) anism from one position to theother, a cam movable by said lever and disposed in and closing said endof the hollow shaft, and means including a rod disposed in the hollowshaft for connecting the cam to said mechanism.

8. In amagneto, of the type in which an armature is moved into and outof contact with magnetic pole pieces, a frame, a hollow shaft mountedtherein and to whichthe armature is fixed, a member fixed to said shaft;an assembly comprising two levers pivotally supported from said shaftfor independent swinging movement, a drive spring interposed. betweensaid levers and tending to swing them apart, and means for limiting theextent of such swinging movement; said as- Sembly being slidable on saidshaft between two extreme positions, means tending to hold said assemblyin one of said positions, means on said frame to control the movement ofsaid assembly from one position to the other, operating connectionsbetween said means and assembly disposed in said hollow shaft, means forapplying a driving force to one of said levers to move it toward theother and stress said spring, the other lever engaging said member, andmeans controlled by the position of said assembly to effect differentdegrees of stressing of said spring.

9. A magneto, comprising, a housing frame of insulating material,primary and secondary coils and a condenser mounted in said frame, ametallic housing for closing one end of said frame and adapted forconnection to an engine, a spring contact mounted on said frame andengaged by the metallic housing, and an electrical connection betweensaid contact and the ground terminals of said coils and condenser.

10. In a magneto, of the type in which an armature is moved into and outof contact with magnetic pole pieces, a frame of insulating material inwhich said pole pieces are mounted, relatively movable breaker points, aplunger which is in metallic connection with one of the breaker pointsand slides in said insulating frame, a metallic housing connected tosaid frame and into which said armature and plunger extend, meansconnected to and insulated from the armature for moving said plunger inone direction, and resilient means engaging said housing and plunger formoving the plunger in the otherdirection and for forming the sole groundconnection for the breaker point plunger.

11. A magneto, comprising, a frame of insulating material; a magneticsource, cores, armature, coils, breaker point mechanism and a condensermounted in said frame; a metallic, lubricant-containing housingconnected to said frame and in turn adapted for connection to an engine,said armature extending into said housing, said mechanism includtendsinto said housing, means connected to and insulated from the armaturefor moving said plunger in one direction, resilient T means connected tosaid housing for moving the plunger in the other direction and alsoforming the sole ground connection for said breaker point, a springcontact on said frame adapted to engage said housing, and metallicconnections from said contact to the ground terminals of said coils andcondenser.

12. In a magneto, a pair of cores, a field magnet extending between theupper ends of said cores and connected thereto, a pair of cross bars oneon each side of said magnet and extending from one core to the other andclamped thereto, each cross bar having a part which extendsoutwardly'therefrom with its lower face no lower than the lower face ofsaid magnet, a frame element on which said parts rest and to which theyare secured, coils on each core extending from the lower face of saidmagnet to a point closely adjacent the lower ends of the cores, and anarmature movable toward and away from said lower ends.

13. In a magneto, a pair of coils arranged side by side in adjacentrelation, a frame element serving to house said coils and beingsubstantially commensurate in height with the length of the coils, apair of cores, one for each coil and passing axially therethrough withtheir lower ends projecting slightly be yond the lower face of saidelement, the upper ends of said cores projecting above the upper face ofsaid element far enough to receive the field magnet, a field magnetinterconnecting said upper ends of the cores and having. its lower facedisposed in closely adjacent relation to the upper ends of said coils, apair of cross harslocated on opposite sides of the core and extendingacross from one tothe other, means for binding said cross bars to thecores, said cross bars having parts extending outwardly therefrom andadapted to rest on and be supported by the upper face of said frameelement, and means for securing said parts to said element.

14:. In a magneto, of the type wherein an armature is moved into and outof cont-act with magnetic pole pieces, primary and secondary windingsassociated with said pole pieces, a normally closed electrical circuitincluding said primary winding, means op-- erated from the armature atan intermediate point in its flight away from said pole pieces to opensaid circuit, a drive shaft, an armature actuating mechanism operativelyinterposed between said shaft and armature, and comprising tworelatively movable members and a drive spring held by said members awayunder a substantial initial stress, said members being relatively movedthrough a relatively short distance by said drive shaft to increase thestress ofsaid drive signatures.

PHELPS BROWN. TERRENGE G. LOUIS.

CERTEFIGAEE 0F CURRECTION.

iatent No. 1,746,378. I Granted February '11, 930, :0

PHELPS BRQWN and TERRENGE G. LQUES.

it is hereby eeriified that the above numbered patent was erreneouslyissued is "Wide Eiectrie Company, e? West Springfield, Massachusetts, aedrperatien 05 Massachusetts", as assignee (ii the Qifiiiffl interest insaid invention, Whereas said patent siwuld have been issued t0 MC:isventers said "Brawn and Louis, said Louis assignof t0 Wise Eieetrie(Jempasy, 0? West Springfield, Massachusetts, a corpora- ;ien eiMassachusetis"; edge 1%, iiiie E27, claim 14-, for the word "away" read"alwsysfl and that the said Lettefs Pateni sheuid be read with ihesecerreetiens therein shai the same may cenierm 0 the recerd of the casein the Fatent ()ffice.

Signed and sealed this 18th day of Marcia, A. D. 1930.

M. 3. Meme, Acting Commissiener 0f Patents.

ceurtrtcers or CGRRECTION.

iateet No. 1,746,378. I Granted February 11, 1930, m

PHELPS aaowu and TERRENCE G. tools.

It is hereby certified that the above numbered patent was erroneouslyissued te "Wieo Electric Company, of West Springfield, Massachusetts, acorporation of Massachusetts", as assignee of the entire interest insaid invention, whereas said patent should have been issued to theinventors said "Brown and Louis, said Louis assiguor to Wico ElectricCompany, of West Springfield, Massachusetts, a corporation ofMassachusetts"; page 10, line 27, claim 14, for the word away" read"always"; and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 18th day of March, A. D. 1930.

M. J. Moore, (Seal) Acting Commissioner of Patents.

